You know what the difference is between zombies in World War Z and “The Walking Dead?” Everything.

Beginning like any other day in Philadelphia, ex-UN worker Gerry Lane (Brad Pitt) finds himself on the run with his family. The cause: an outbreak transmitted through a bite that turns a human into a rabid, frenzying carrier intent on infecting anyone and everyone it can. A fleet of ships in the Atlantic serves as a base of operation as US cities and more all over the globe are falling to the epidemic, but a handful of specialists think a cure could be had if they could find “patient zero.” With the safety of his family hanging in the balance, Gerry reluctantly accompanies a team across the globe in an effort to discover the cause and a cure, but is it already too late?

Putting the worst parts of 28 Days Later and Contagion into a blender would be a good start to describe what unfolds onscreen, but the most baffling part is the lack of actual blood. The zombie-like affliction seems to have one purpose: infect everyone, but then what? These things don’t eat so much as they infect and move on, but at the speeds they move – like cockroaches scattering when a light comes on – they can’t possibly last very long. To quote Bladerunner, “A candle that burns twice as bright burns half as long,” and if you suddenly turned into a sprinting, climbing infection machine running full tilt for hours on end, how long before your heart exploded? The science for the effect is pure fiction here, which hurts the overall production since the plot is driven by investigators trying to make sense out of all of it. It’s an action-thriller zombie film purged of blood, gore, and most of the drama, and yet it remains surprisingly watchable as an edge-of-your-seat, will-they-or-won’t-they-make-it summer popcorn flick.

It’s no secret that the production was reportedly riddled with issues, from a bungled third act to skyrocketing location shoot costs. Throughout it all, the one positive thing was Brad Pitt taking it all in stride, shown helping out not only on set between takes but getting out to pitch this film at various screenings to rally support. As the only real A-lister on the casting sheet, he shouldered the lion’s share of the production and success of the film, and where it has legs can probably be credited to Pitt due to sheer will. For an intended summer blockbuster, it works; whether or not it can sustain any intended sequels remains to be seen.

It was also reported that the biggest failing of the film – other than almost no resemblance to the book that inspired it by Max Brooks – was the third act and ending. It didn’t make any sense, and so specialists were hired to get it fixed, not unlike Pitt’s character in the film. You can almost see where the line was drawn, when the action grinds to a halt and everyone puts their thinking caps on. Of course, the looniest long shot possible is the one tried and, of course, meets with a measurable degree of success. This is the opposite of Contagion – a film that was almost too big to keep its plot confined within its running time – where the scientists failed a lot before a glimmer of hope ever appeared. If you prefer your medical science fiction and zombie films with drama and dread, stick to AMC. If you want to dip your toe in for a couple of hours before finding an imaginary teardrop in a swimming pool, Brad Pitt has made the definitive zombie film for people who don’t like zombie films yet want to say they liked one.

(a two skull recommendation out of four)